Automatic press for die blanking of two concentric parts from steel strips

ABSTRACT

An automatic press for die blanking two concentric parts from a steel strip. The press is provided with compound dies whose blanking surfaces are arranged vertically, the dies being positioned one above the other. The punches of the dies are secured on slides articulated to provide reciprocal movement in opposite directions. There are also feed devices provided above the respective dies for the periodic feed by gravity of workpieces to the upper dies and of central portions blanked in the upper die to the lower dies. A mechanism is coordinated with the slide movement so that the workpieces are fed from the feed devices when the dies are opened and the finished parts are removed from the die punches when the dies are opened.

United States Patent 1 Gilev et al.

[ 1 July 24, 1973 [54] AUTOMATIC PRESS FOR DIE BLANKING OF TWO CONCENTRIC PARTS FROM STEEL STRIPS [76] Inventors: Vitaly Konstantinovich Gilev, 8ll

proezd, 65, kv. 16; Volt Nakhimovich Evzlin, ulitsa Chapaeva, 102, kv. 53; Rafael Tevosovieh Sarkisov, ulitsa Aga-Neimatully, 20a, blok 3, kv. 28; Ernst Arakelovich Stepanian, ulitsa Druzhby Molodezhi, 2, kv. 36, all of Baku, U.S.S.R.

[22] Filed: Jan. 12, 1972 21 Appl. No.: 217,305

Related US. Application Data [63] Continuation of Ser. No. 865,358, Oct. 10, 1969.

[52] US. Cl 83/132, 83/135, 83/165,

' 83/255, 83/268, 83/405, 83/519, 83/618 [51] Int. Cl B261 l/02, 826d 11/00 [58] Field of Search 83/519, 513, 618,

[56] Reterences Cited UNITED STATES PATENTS 559,500 5/1896 Sternbergh 83/618 X Primary Examiner-Frank T. Yost Attorney-Waters, Roditi, Schwartz & N issen [57] ABSTRACT An automatic press for die blanking two concentric parts from a steel strip. The press is provided with compound dies whose blanking surfaces are arranged vertically, the dies being positioned one above the other. The punches of the dies are secured on slides articulated to provide reciprocal movement in opposite directions. There are also feed devices provided above the respective dies for the periodic feed by gravity of workpieces to the upper dies and of central portions blanked in the upper die to the lower dies. A mechanism is coordinated with the slide movement so that the workpieces are fed from the feed devices when the dies are opened and the finished parts are removed from the die punches when the dies are opened.

7 Claims, 6 Drawing Figures AUTOMATIC PRESS FOR DIE BLANKING OF TWO CONCENTRIC PARTS FROM STEEL STRIPS This is a continuation of application Ser. No. 865,358, filed Oct. 10, 1969.

The present invention relates to automatic presses for die blanking of two concentric parts from steel strips to manufacture stator and rotor sheets of magnetic circuits of electric machines.

Known in the art are automatic presses for die blanking of two concentric parts formed from steel strips, and which are provided with two compound dies, one above the other, whose blanking surfaces are arranged vertically. The punches of the dies are fixed on slides driven in reciprocal movement in opposite directions.

Such presses blank concentric parts formed from steel strips which are fed to a blanking zone by a suction unit which picks a strip up out of a pile, turns it into a vertical position and displaces along a rib toward a roll feed magazine for the subsequent feed of the strip to the blanking zone by a blanking pitch.

However, the provision of a suction unit operating in a complex two coordinate reciprocating motion results in reduction of the number of press strokes. The presence of a table with a feed system and vacuum devices essentially reduces the press efficiency due to an increase in the period of time required for the press maintenance. Besides, the required intricacy of a system exercising control over the position of a lower die plate, upon which an upper stator die isprovided, andwhich is designed to arrange a strip to the level of rolls, extends the time required for the adjustment of the dies. The provision of a roll feed and related mechanisms such as a strip pulling mechanism and a dividing mechanism required to feed and move a strip or band along its rib by a blanking pitch within a blanking zone precludes the possibility of the simultaneous blanking of, for example, two stator sheets by two stator dies fixed on an upper slide.

it is an object of the present invention to provide an automatic press which facilitate the blending of two concentric parts from the previously blanked sheet workpieces. Another object of the invention is to provide a press which eliminates the need for additional arrangements to feed a workpiece into an opened die, and to thereby maintain the production efficiency.

A further object of the invention is to provide a press wherein sheet workpieces are fed by gravity to an opened die and in synchronism with the movement of slides.

According to the above-stated and other objects, in an automatic press for the die blanking of two concentric parts formed from a sheet workpiece, which comprises compound dies positioned one above the other and having vertically arranged blanking surfaces, the punches of said dies being fixed on slides performing reciprocal movement in opposite directions, the invention provides for first feed means located above theupper die for feeding workpieces thereto by gravity when the die is opened, second feed means located between the dies for receiving the blanked central portion produced in the upper die and feeding the same to the lower die by gravity when the lower die is opened, and means synchronizing the periodic feed of the workpieces into the opened dies and the removal of the completed parts from the die punches with the movement of the slides.

Such solution of the problem of the invention provides an automatic operating cycle for feeding workpieces into the dies while removing completed parts therefrom, as well as provides for an increase in the number of operative slide strokes as compared with the known types of presses. Moreover the conveyance of workpieces with the present arrangements into the opened dies in synchronism with the movement of the slides and the removal of completed parts from the die punches ensures the orderly motion of the workpieces and parts while concurrently achieving division of the workpieces and the completed parts produced in the upper die into two independent conveying flows during the gravity feed of the workpieces: the blanked central portions are periodically fed provide conveyance into the lower die, and the blanked peripheral portions are removed from the upper die punches and fed as finished stator parts along a chute for stacking.

It is preferred that each of the feed means for the periodic conveyance of workpieces is formed by two flats interconnected by a spring, one of those flats being fixed and positioned vertically, and the other flat being pivotable and mounted at an incline to the former flat for engagement therewith.

Each device synchronizing the periodic conveyance of workpieces from the feed means with the movement of the slides may be fashioned as a lever with a cam on one of its ends, said lever being turnable on a slide, and a roller regularly interacting with the cam during the slide motion, said roller being mounted on a bracket which is fastened to the feed means.

It is desirable that the bracket with the roller be fixed on the pivotable flat of the feed means.

It is also desirable that each device synchronizing the removal of the completed parts with the slide movement be in the form of a pair of pushers periodically interacting during the motion of the slides, one of the pushers being secured on an arm hinged to the slides and the other pusher on a spring-biased plate mounted in a slide, and the plate having fingers for interacting with a mechanism adapted to remove completed parts from the dies.

Such a solution of the problem of the invention assists in greatly increasing the press efficiency, while the use of pre-blanked workpieces gravity-fed to a blanking zone considerably simplifies the construction of the press and reduces its weight since this obviates the necessity of cutting and piling strips and of having to provide mechanisms for feeding them into the die.

The invention will be more apparent from an exemplary embodiment of an automatic press for blanking stator and rotor sheets for electric machines, reference being had to the appended drawings, wherein:

FIG. 1 is a side elevational view, partly in crosssection, of the presse of the invention;

FIG.2 is an enlarged sectional view of the guides for the columns of the press slides;

FlG.3 is a side view, partly in section, of device for periodically conveying blanks into the press die;

FIG. 4 is a front view of the device shown in FIG. 3;

FIG. 5 is a side view of device for synchronizing the periodic conveyance of blanks into the press dies with the movement of the slides; and

FIG. 6 is a side view, partly in section, of a device synchronizing the removal of completed parts from the press die punches with the movement of the slides.

The automatic press for blanking, for example, stator and rotor parts from workpieces comprises a bedplate l (FlG.l) whereon upper die plates 2 and lower die plates 3 are secured and vertically arranged one above the other.

The press includes compound dies with vertically arranged blanking surfaces, the upper of these dies being intended for blanking stator sheets and the lower one for punching rotor sheets. The matrices 4 and 5 of these dies are fixed on the plates 2 and 3, respectively, and punches 6 and 7 are mounted on slides, each slide comprising a front cross-piece 8 and a rear cross-piece 9, both being interconnected by means of columns 10.

In order to increase the efficiency of the press, there may be provided more than one set of stator and rotor dies, the vertical positioning of the blanking surfaces and arrangement of the dies one above the other permitting automatic blanking, while taking advantage of the gravity feed of the workpieces to the blanking zone.

The slides are driven in reciprocal movement in opposite directions from a connecting rod 11, one end of which is hinged to rear cross-piece 9 and the other end of which is engaged with an eccentric 12 the latter of which is provided on a shaft 13 of a spiral gear 14. The gear 14 has imparted thereto rotation from an intermediate gear 15 which, in turn, is rotated by an electric motor 16 through a V-belt drive 17, with the eccentrics 12 being mounted so that their eccentricities extend in opposite directions.

In order to facilitate the displacement of the columns 10 during the. slide motion, provision is made in the bedplate l for channels 18 (H02) in which, on a spiral line (not shown in the drawings), is housed a separator 19 having ball bearings 20. The provision of the ball bearings 20 for the columns 10 of the slides reduces the play of the columns during the slide movement, which extends the life of the dies and thereby ensures the high precision of the parts being blanked, while the provision of the ball bearings 20 on the spiral line reduces the wear of the surfaces of the columns 10 and channels 18.

Provided above each of the dies in the press are feed means 21 and 22 (FlG.1) intended respectively for periodic conveyance of workpieces into the upper die and of workpieces into the lower die.

Furthermore, there are included devices 23 and 24 in the press, which are intended to synchronize with the slide movement, the periodic conveyance of workpieces from the feed means 21 and 22 into the opened dies, as well as a device 25 synchronizing with the slide movement the removal of completed parts from the die punches 6 and 7.

The positioning of the feed means 21 and 22 above the respective dies permits feed of the workpieces into the blanking zones, whereas the presence of the synchronizing devices 23, 24, and 25 effects the automated cycle of introducing the workpieces and removing completed parts or sheets, as well as the separation of completed stator sheets and blanked central portions into two independent flows, the central portions serving as workpieces for the manufacture of rotor sheets in the lower die.

Both of the feed means 21 and 22 for the periodic conveying of workpieces are formed by two flats 26 and 27 (FIG. 3). The flats 26 and 27 are interconnected by a spring 28. The flat 26 is fixed and positioned vertically on the bedplate 1 (not shown in the figure), while the flat 27 is inclined relative to the flat 26 and may be moved so as to adjoin the former, the flat 27 being pivotable about an axle 29 (FIGA) which is secured on brackets 30 of the bedplate 1.

Both of the devices 23 and 24 (FIG.1) adapted for synchronizing with the slide movement the periodic conveyance of workpieces from the feed means 21 and 22, respectively, are each fashioned as a lever 31 having a cam plate 32, said lever being pivotable on the front cross-piece 8 (FIGS), and a roller 33 located on a bracket 34 (FIG.3) which is secured on the pivotable flat 27. The camplate 32 (FlG.5) periodically coacts with the roller 33.

The lever 31 has a groove 35 adapted to accommodate a slide piece 36 through which passes the axle of rotation 37 of the lever 31. This axle 37 also extends through a post 38 which is secured on the cross-piece 8. The slide piece 36 is fitted with a screw 39 having nuts 40 and 41 permitting the movement and positioning of the lever 31 relative to the slide piece 36.

Furthermore, adjustment of the position of the lever 31 relative to the cross-piece 8 is possible with the assistance of an adjustment screw 42. The cam-plate 32 is secured on the lever 31 so as to be rotatable relative to the axle 43. The position of the cam-plate 32 is fixed by means of a screw 44.

The above described displacements are required in order to control the moment of opening of the feed means 21 and 22 in coordination with the opening of the dies.

The device 25 (FIG.1) for synchronizing with the slide movement the removal of completed parts from the die punches 6 and 7, includes two pairs of pushers 45 and 46 which periodically interact during the slide movement, of which pushers 45, are secured on a rocker 47 and the pushers 46, are located on springbiased plates 48 positioned in the forward cross-pieces 8 of the slides. The rocker 47 is hinged to the forward cross-pieces 8 of the slides. The plates 48 have fingers 49 for interacting with a mechanism (not shown) for picking up completed parts. The pushers 45 are formed as pins which are screwed into the rocker 47, which allows adjustment of the interval of operating the mechanism for removing completed parts during the final period of the opening of the dies.

The automatic press of the invention operates as follows:

From the electric motor 16 (F161), through the V- belt drive 17, rotation is imparted to the intermediate gear 15. The latter imparts rotation to the two spiral gears 14. The connecting rods 11, whose ends are located on the eccentrics 12 provided on the shafts 13 of said spiral gears 14, are hinged, at their other ends, to

the rear cross-pieces 9 of the slides and transmit reciprocating motion to them in opposite directions in response to the arrangement of the eccentrics 12 whose eccentricities extend in opposite directions, whereby the operation of the press results in successive openings and closings of the upper and lower dies.

A predetermined number of stacked stator and rotor sheets are concurrently blanked blanked in the upper and lower dies, respectively, the upper die blanking a peripheral completed part of the stator sheet out ofa round workpiece, the central portion serving as a workpiece for the rotor part which is then fed to the lower die for blanking.

The blanking of the stator sheets and rotor sheets is effected from pre-fabricated round workpieces 50, said round workpieces being supplied from an upper location into the feed means 21 by a belt conveyor (not shown in the figures). In the feed means 21, a round workpiece 50 is held in a vertical position, being pressed against the stationary vertical flat 26 by the flat 27.

The opening of the feed means 21 is synchronized with the slide movement through the action of the device 23. As the punch 6 approaches the matrix 4 of the upper die, the cam-plate 32 (FIGS) of the device 23 which is secured on the cross-piece 8, comes into contact with the roller 33 so that the cam-plate 32 contacts the roller 33 with its lower surface. As a result the lever 31 turns to some degree in a counter-clockwise direction about the axle 37. Once both halves of the upper die meet completely, they blank from the workpiece 50, a finished stator sheet and a central portion which serves as a workpiece for the lower die to produce rotor parts.

Simultaneously, the cam-plate 32 fully passes above the roller 33, the lever 31 returns to its initial position, supported by the screw 39 on the cross-piece 8, and the roller 33 moves out onto the upper surface of camplate 32.

When the upper die is opened, i.e., the punch 6 (FlG.l) travels away from the matrix 4, a stator sheet which has been blanked in the upper die remains on the punch 6 pending the complete opening of the die, while the round rotor workpiece falls into the feed means 22 and remain there until the device 24 is operated. Simultaneously, the roller 33 (F165) of the device 23 moves upwardly along the upper surface of the cam-plate 32 thereby, pulling the flat 27 (FlG.3). The flat 27 turns clockwise about the axle 29 (F104) and disengages from the plate 26 thereby stretching the spring 28 (FIG.3) and forming an open slot. disengages workpiece 50 (FlG.l) then falls into the opening die and is fastened onto the matrix 4. Subsequently, the roller 33 (FIGS) disengages from the cam 31 during the course of its further displacment along said cam, and the stressed spring 28 (FlG.3), returns the flat 27 into its initial position, i.e., the flat 27 is pressed against the flat 26.

The feed means 21 is then ready to receive a successive round workpiece.

During the last interval of the upper die disengagement, the device 25 (FlG.l) comes into operation, synchronizing with the movement of the slides the removal of completed stator sheet parts which have been blanked out of a workpiece positioned in the upper die during the previous cycle Upon that occurrence, the pusher 45 (FlG.6) moves into engagement with the pusher 46 and exerts pressure on the latter. The through the spring-biased plate 48 is then displaced to cause the fingers 49 to engage a removing mechanism (not shown) provided on the die punch. This mechanism removes a completed stator sheet (not shown) from the die punch and drops it onto a chute 51 (FlG.l) along which said sheet is removed from the press.

With the punch 6 approaching the matrix 4 during the closure of the upper die, the pusher 45 (FIG.6) disengages from the pusher 46 during the rotation of the rocker 47 (as the slides proceed in opposite directions), while the springs 52 return the plate 48 to its initial position. Subsequently, a stator sheet 53 (shown in dotted line in the figure) and a central portion 54, i.e., a workpiece for a rotor sheet, are blanked from the workpiece 50 (FlG.l) which is secured on the matrix 4 during the complete closure of the die.

At the same time, the punch 7 of the lower die moves away from the matrix 5 whereby the lower die proceeds to disengage. This results in operation of the device 24 in a manner similar to that of the operation of the device 23, the feed means 22 opening as in the case with the feed means 21. Once feed means 22 is opened, a workpiece (not shown) for the rotor sheet, which is previously positioned therein, drops onto the matrix 5 of the opening lower die. The completed rotor sheet part blanked during the previous cycle remains on its punch pending the complete opening of the lower die and is removed from the punch after a sequential pair of the pushers 45 and 46 of the device 25 commence their interaction, said pushers operating in the same manner as the previously described pair. The rotor sheet is then conveyed outside of the press along the chute 55.

Once the direction of the movement of the upper and lower-die punches is reversed, i.e., the lower die is closed and the upper die opened, the workpiece 54 (FlG.l) for the rotor sheet drops into the feed means 22, the pivotable flat 27 again adjoins the flat 26 at that moment and the finished stator sheet 53 is taken from the punch 6 and carried from the press along the chute 51. Simultaneously, the lower die, while closing, blanks a rotor sheet out of a workpiece which was positioned within the blanking zone during the previous cycle (not shown in the figures), while a stator sheet and a workpiece for a rotor sheet from a successive workpiece positioned within the blanking zone during the opening of the feed means 21 is blanked in the closing upper die.

When the direction of the punch movement is reversed, the lower die is opened, and the finished rotor sheet 55 produced from the workpiece 54 falls onto the chute 56 and is removed from the press.

The cycle of blanking stator and rotor sheets thus repeats itself.

The methods and devices described hereinabove provide in the press of the invention a cycle of feeding workpieces into the dies and removing finished parts which is completely automatic.

What we claim is:

1. An automatic press for die blanking workpiece sheets to produce motor and stator parts therefrom, said press comprising a bedplate, upper die means for cutting workpiece sheets to produce central rotor blanks and peripheral stator parts from the workpiece sheets, lower die means arranged under the upper die means in a common vertical plane for receiving the rotor blanks from the upper die means and for producing finished rotor parts from said rotor blanks, said die means including respective die matrices secured to said bedplate and die punches opposite said matrices, slides respectively supporting said die punches, means coupled to said slides to reciprocally move the same to open and close said upper and lower die means in alternation, first feed means located above the upper die means for feeding workpiece sheets by gravity to said upper die means, second feed means located between the upper and lower die means for receiving the rotor blanks from the upper die means and for feeding said blanks by gravity to the lower die means, means coupled to said first and second feed means for synchronizing the operation thereof with the movement of the slides so that the workpiece sheets and rotor blanks are respectively fed to the upper die means and lower die means when they are opened, and means for removing the finished stator and rotor parts from said upper and lower die means in synchronization with the movement of said slides when the die means are opened.

2. A press as claimed in claim 1, wherein said first and second feed means each comprises two flat members, and a spring interconnecting said flat members and urging the same together, one of said flat members being fixed and vertical and the other pivotable and inclined relative to the first.

3. A press as claimed in claim 2, wherein said means for synchronizing the operation of the first and second feed means with the movement of the slides comprises for each feed means a lever having opposite ends, and a cam-plate on one of the ends of said lever, said lever being pivotably mounted on its associated slide, each feed means comprising a roller periodically interacting with its respective cam-plate during movement of the slide for the periodic feed of the workpieces or blanks.

4. A press as claimed in claim 3, wherein each feed means comprises a bracket supporting a respective roller, said bracket being mounted on the pivotable flat member of the particular means to open the flat members against the opposition of the spring and permit the workpieces or blanks to drop by gravity to the underlying feed means.

5. A press as claimed in claim 1, wherein the means for removing the finished stator and rotor parts comprises for each die means a pair of pushers periodically engaged during the movement of the associated slides, a rocker hinged on each slide and supporting one associated pusher, a spring-biased plate mounted on said slide and including fingers for interacting with a mechanism for removng finished parts from the associated die means, the other pusher being secured to said springbiased plate and being periodically engaged by the first pusher during the reciprocal movement of the slide.

6. A press as claimed in claim 1, comprising chute means positioned beneath each die means for conveying the finished parts therefrom after removal from said die means.

7. A press as claimed in claim 1, wherein each feed means comprises a pair of displaceable members which holds the associated workpiece sheet or rotor blank in preparation for opening of the associated die means whereafter the displaceable members are relatively moved to open position to permit the workpiece sheet or rotor blank to drop by gravity to the associated feed means. V 

1. An automatic press for die blanking workpiece sheets to produce motor and stator parts therefrom, said press comprising a bedplate, upper die means for cutting workpiece sheets to produce central rotor blanks and peripheral stator parts from the workpiece sheets, lower die means arranged under the upper die means in a common vertical plane for receiving the rotor blanks from the upper die means and for producing finished rotor parts from said rotor blanks, said die means including respective die matrices secured to said bedplate and die punches opposite said matrices, slides respectively supporting said die punches, means coupled to said slides to reciprocally move the same to open and close said upper and lower die means in alternation, first feed means located above the upper die means for feeding workpiece sheets by gravity to said upper die means, second feed means located between the upper and lower die means for receiving the rotor blanks from the upper die means and for feeding said blanks by gravity to the lower die means, means coupled to said first and second feed means for synchronizing the operation thereof with the movement of the slides so that the workpiece sheets and rotor blanks are respectively fed to the upper die means and lower die means when they are opened, and means for removing the finished stator and rotor parts from said upper and lower die means in synchronization with the movement of said slides when the die means are opened.
 2. A press as claimed in claim 1, wherein said first and second feed means each comprises two flat members, and a spring interconnecting said flat members and urging the same together, one of said flat members being fixed and vertical and the other pivotable and inclined relative to the first.
 3. A press as claimed in claim 2, wherein said means for synchronizing the operation of the first and second feed means with the movement of the slides comprises for each feed means a lever having opposite ends, and a cam-plate on one of the ends of said lever, said lever being pivotably mounted on its associated slide, each feed means comprising a roller periodically interacting with its respective cam-plate during movement of the slide for the periodic feed of the workpieces or blanks.
 4. A press as claimed in claim 3, wherein each feed means comprises a bracket supporting a respective roller, said bracket being mounted on the pivotable flat member of the particular means to open the flat members against the opposition of the spring and permit the workpieces or blanks to drop by gravity to the underlying feed means.
 5. A press as claimed in claim 1, wherein the means for removing the finished stator and rotor parts comprises for each die means a pair of pushers periodically engaged during the movemEnt of the associated slides, a rocker hinged on each slide and supporting one associated pusher, a spring-biased plate mounted on said slide and including fingers for interacting with a mechanism for removng finished parts from the associated die means, the other pusher being secured to said spring-biased plate and being periodically engaged by the first pusher during the reciprocal movement of the slide.
 6. A press as claimed in claim 1, comprising chute means positioned beneath each die means for conveying the finished parts therefrom after removal from said die means.
 7. A press as claimed in claim 1, wherein each feed means comprises a pair of displaceable members which holds the associated workpiece sheet or rotor blank in preparation for opening of the associated die means whereafter the displaceable members are relatively moved to open position to permit the workpiece sheet or rotor blank to drop by gravity to the associated feed means. 